RESUMEN

Lipodystrophic laminopathies are a group of ultra-rare disorders characterised by the presence of pathogenic variants in the same gene (LMNA) and other related genes, along with an impaired adipose tissue pattern and other features that are specific of each of these disorders. The most fascinating traits include their complex genotype-phenotype associations and clinical heterogeneity, ranging from Dunnigan disease, in which the most relevant feature is precisely adipose tissue dysfunction and lipodystrophy, to the other laminopathies affecting adipose tissue, which are also characterised by the presence of signs of premature ageing (Hutchinson Gilford-progeria syndrome, LMNA-atypical progeroid syndrome, mandibuloacral dysplasia types A and B, Nestor-Guillermo progeria syndrome, LMNA-associated cardiocutaneous progeria). This raises several questions when it comes to understanding how variants in the same gene can lead to similar adipose tissue disturbances and, at the same time, to such heterogeneous phenotypes and variable degrees of metabolic abnormalities. The present review aims to gather the molecular basis of adipose tissue impairment in lipodystrophic laminopathies, their main clinical aspects and recent therapeutic strategies. In addition, it also summarises the key aspects for their differential diagnosis.

Asunto(s)

Lamina Tipo A , Laminopatías , Lipodistrofia , Progeria , Humanos , Progeria/genética , Progeria/patología , Lamina Tipo A/genética , Lamina Tipo A/metabolismo , Lipodistrofia/genética , Lipodistrofia/metabolismo , Lipodistrofia/patología , Laminopatías/genética , Tejido Adiposo/metabolismo , Tejido Adiposo/patología , Fenotipo , Mutación

RESUMEN

Recent research into laminopathic lipodystrophies-rare genetic disorders caused by mutations in the LMNA gene-has greatly expanded our knowledge of their complex pathology and metabolic implications. These disorders, including Hutchinson-Gilford progeria syndrome (HGPS), Mandibuloacral Dysplasia (MAD), and Familial Partial Lipodystrophy (FPLD), serve as crucial models for studying accelerated aging and metabolic dysfunction, enhancing our understanding of the cellular and molecular mechanisms involved. Research on laminopathies has highlighted how LMNA mutations disrupt adipose tissue function and metabolic regulation, leading to altered fat distribution and metabolic pathway dysfunctions. Such insights improve our understanding of the pathophysiological interactions between genetic anomalies and metabolic processes. This review merges current knowledge on the phenotypic classifications of these diseases and their associated metabolic complications, such as insulin resistance, hypertriglyceridemia, hepatic steatosis, and metabolic syndrome, all of which elevate the risk of cardiovascular disease, stroke, and diabetes. Additionally, a range of published therapeutic strategies, including gene editing, antisense oligonucleotides, and novel pharmacological interventions aimed at addressing defective adipocyte differentiation and lipid metabolism, will be explored. These therapies target the core dysfunctional lamin A protein, aiming to mitigate symptoms and provide a foundation for addressing similar metabolic and genetic disorders.

Asunto(s)

Lamina Tipo A , Lipodistrofia , Humanos , Lamina Tipo A/genética , Lamina Tipo A/metabolismo , Lipodistrofia/genética , Lipodistrofia/metabolismo , Lipodistrofia/terapia , Animales , Laminopatías/genética , Laminopatías/metabolismo , Progeria/genética , Progeria/metabolismo , Progeria/patología , Mutación , Lipodistrofia Parcial Familiar/genética , Lipodistrofia Parcial Familiar/metabolismo , Lipodistrofia Parcial Familiar/terapia , Metabolismo de los Lípidos/genética , Tejido Adiposo/metabolismo , Tejido Adiposo/patología , Resistencia a la Insulina/genética , Edición Génica

RESUMEN

INTRODUCTION: First reports associated mutations in triggering receptors expressed on myeloid cells 2 (TREM2) with autosomal recessive Nasu-Hakola disease characterized by painful bone cysts and progressive presenile dementia with psychotic symptoms; however, recent TREM2 biallelic rare variants are suggested to be causative also for the behavioral variant of frontotemporal dementia (bvFTD) without bone involvement. MATERIAL AND METHODS: Clinical data of three unrelated bvFTD patients carrying TREM2 biallelic variants were evaluated. All patients underwent neurological, psychiatric, and cognitive evaluation and neuroimaging. A full neuropsychological assessment was performed in two cases. RESULTS: Two patients carried compound heterozygous TREM2 variants, p.R62C and p.T66M, and one carried the homozygous p.D87N variant. Based on all obtained clinical and neuroimaging data, a behavioral variant of frontotemporal dementia was diagnosed in all cases. Their clinical manifestation was typical with neuropsychiatric and cognitive features, without bone abnormalities. CONCLUSIONS: Despite all three subjects partially resembling clinical manifestations of Nasu-Hakola disease with TREM2 mutations, we reveal some distinct features, including age of onset, neuroimaging findings, or disease course.

Asunto(s)

Demencia Frontotemporal , Glicoproteínas de Membrana , Receptores Inmunológicos , Humanos , Demencia Frontotemporal/genética , Demencia Frontotemporal/patología , Receptores Inmunológicos/genética , Glicoproteínas de Membrana/genética , Masculino , Femenino , Persona de Mediana Edad , Mutación/genética , Panencefalitis Esclerosante Subaguda/genética , Adulto , Osteocondrodisplasias/genética , Lipodistrofia/genética

RESUMEN

Introduction: Lipodystrophy syndromes are rare diseases that can present with a broad range of symptoms. Delays in diagnosis are common, which in turn, may predispose to the development of severe metabolic complications and end-organ damage. Many patients with lipodystrophy syndromes are only diagnosed after significant metabolic abnormalities arise. Prompt action by clinical teams may improve disease outcomes in lipodystrophy syndromes. The aim of the Rapid Action Plan is to serve as a set of recommendations from experts that can support clinicians with limited experience in lipodystrophy syndromes. Methods: The Rapid Action Plan was developed using insights gathered through a series of advisory meetings with clinical experts in lipodystrophy syndromes. A skeleton template was used to facilitate interviews. A consensus document was developed, reviewed, and approved by all experts. Results: Lipodystrophy is a clinical diagnosis. The Rapid Action Plan discusses tools that can help diagnose lipodystrophy syndromes. The roles of clinical and family history, physical exam, patient and family member photos, routine blood tests, leptin levels, skinfold measurements, imaging studies, and genetic testing are explored. Additional topics such as communicating the diagnosis to the patients/families and patient referrals are covered. A set of recommendations regarding screening and monitoring for metabolic diseases and end-organ abnormalities is presented. Finally, the treatment of lipodystrophy syndromes is reviewed. Discussion: The Rapid Action Plan may assist clinical teams with the prompt diagnosis and holistic work-up and management of patients with lipodystrophy syndromes, which may improve outcomes for patients with this rare disease.

Asunto(s)

Lipodistrofia , Humanos , Lipodistrofia/diagnóstico , Lipodistrofia/terapia , Lipodistrofia/genética , Manejo de la Enfermedad , Síndrome

RESUMEN

Background: Lipodystrophy is a rare disease that is poorly diagnosed due to its low prevalence and frequent phenotypic heterogeneity. The main therapeutic measures for patients with clinical lipodystrophy are aimed at improving general metabolic complications such as diabetes mellitus, insulin resistance, and hypertriglyceridemia. Therefore, there is an urgent need to find new biomarkers to aid in the diagnosis and targeted treatment of patients with congenital generalized lipodystrophy (CGL). Methods: Dataset GSE159337 was obtained via the Gene Expression Omnibus database. First, differentially expressed genes (DEGs) between CGL and control samples were yielded via differential expression analysis and were analyzed for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment to explore the functional pathways. Next, protein-protein interaction analysis and the MCC algorithm were implemented to yield candidate genes, which were then subjected to receiver operating characteristic (ROC) analysis to identify biomarkers with an area under the curve value exceeding 0.8. Moreover, random forest (RF), logistic regression, and support vector machine (SVM) analyses were carried out to assess the diagnostic ability of biomarkers for CGL. Finally, the small-molecule drugs targeting biomarkers were predicted, and ibuprofen was further validated in lipodystrophy mice. Results: A total of 71 DEGs in GSE159337 were sifted out and were involved in immune receptor activity, immune response-regulating signaling pathway, and secretory granule membrane. Moreover, CXCR2, TNFSF10, NLRC4, CCR2, CEACAM3, TLR10, TNFAIP3, and JUN were considered as biomarkers by performing ROC analysis on 10 candidate genes. Meanwhile, RF, logistic regression, and SVM analyses further described that those biomarkers had an excellent diagnosis capability for CGL. Eventually, the drug-gene network included ibuprofen-CXCR1, ibuprofen-CXCR1, cenicriviroc-CCR2, fenofibrate-JUN, and other relationship pairs. Ibuprofen treatment was also validated to downregulate CXCR1 and CXCR2 in peripheral blood mononuclear cells (PBMCs) and improve glucose tolerance, hypertriglyceridemia, hepatic steatosis, and liver inflammation in lipodystrophy mice. Conclusion: Eight biomarkers, namely, CXCR2, TNFSF10, NLRC4, CCR2, CEACAM3, TLR10, TNFAIP3, and JUN, were identified through bioinformatic analyses, and ibuprofen targeting CXCR1 and CXCR2 in PBMCs was shown to improve metabolic disturbance in lipodystrophy, contributing to studies related to the diagnosis and treatment of lipodystrophy.

Asunto(s)

Biología Computacional , Animales , Ratones , Biología Computacional/métodos , Humanos , Lipodistrofia/genética , Lipodistrofia/tratamiento farmacológico , Lipodistrofia/metabolismo , Biomarcadores/metabolismo , Biomarcadores/análisis , Masculino , Mapas de Interacción de Proteínas , Perfilación de la Expresión Génica , Ratones Endogámicos C57BL

Asunto(s)

Lipodistrofia , Fenotipo , Humanos , Lipodistrofia/diagnóstico , Lipodistrofia/epidemiología , Lipodistrofia/genética , Prevalencia

RESUMEN

BACKGROUND: The Triggering Receptor Expressed on Myeloid Cells 2 protein (TREM2) plays a crucial role in various biological processes, including osteoclast differentiation, and disease-associated microglia (DAM) activation to regulate neuroinflammation, and phagocytosis in the brain. Genetic variations in TREM2 are implicated in neurodegenerative disorders, such as Nasu-hakola disease (NHD), characterized by bone lesions, neuropsychiatric disorders, and early-onset dementia. METHODS: We studied 3 siblings with suspected NHD. Whole-exome sequencing was conducted on the proband to identify the possible genetic cause(s) and by Sanger sequencing to validate the identified variants in the two other affected siblings, a healthy sister, and the parents. RESULTS: We identified a novel homozygous deletion (c.549del; p.(Leu184Serfs*5)) in TREM2. Our literature review reveals 16 TREM2 mutations causing early-onset dementia and bone lesions. CONCLUSION: These findings, alongside previous research, elucidate the clinical spectrum of TREM2-related diseases, aiding accurate diagnosis and patient care. This knowledge is vital for understanding TREM2-dependent DAM and its involvement in the pathogenesis of neurodevelopmental disorders which can help to develop targeted therapies and improve outcomes for TREM2-affected individuals.

Asunto(s)

Homocigoto , Lipodistrofia , Glicoproteínas de Membrana , Osteocondrodisplasias , Receptores Inmunológicos , Hermanos , Panencefalitis Esclerosante Subaguda , Femenino , Humanos , Consanguinidad , Lipodistrofia/genética , Lipodistrofia/patología , Glicoproteínas de Membrana/genética , Osteocondrodisplasias/genética , Osteocondrodisplasias/patología , Linaje , Receptores Inmunológicos/genética , Panencefalitis Esclerosante Subaguda/genética , Panencefalitis Esclerosante Subaguda/patología

RESUMEN

Lipomatoses are benign proliferation of adipose tissue. Lipomas (benign fat tumors) are the most common component of lipomatosis. They may be unique or multiple, encapsulated or not, subcutaneous or sometimes visceral. In some cases, they form large areas of non-encapsulated fat hypertrophy, with a variable degree of fibrosis. They can develop despite the absence of obesity. They may be familial or acquired. At difference with lipodystrophy syndromes, they are not associated with lipoatrophy areas, except in some rare cases such as type 2 familial partial lipodystrophy syndromes (FPLD2). Their metabolic impact is variable in part depending on associated obesity. They may have functional or aesthetic consequences. Lipomatosis may be isolated, be part of a syndrome, or may be visceral. Isolated lipomatoses include multiple symmetrical lipomatosis (Madelung disease or Launois-Bensaude syndrome), familial multiple lipomatosis, the painful Dercum's disease also called Adiposis Dolorosa or Ander syndrome, mesosomatic lipomatosis also called Roch-Leri lipomatosis, familial angiolipomatosis, lipedema and hibernomas. Syndromic lipomatoses include PIK3CA-related disorders, Cowden/PTEN hamartomas-tumor syndrome, some lipodystrophy syndromes, and mitochondrial diseases, especially MERRF, multiple endocrine neoplasia type 1, neurofibromatosis type 1, Wilson disease, Pai or Haberland syndromes. Finally, visceral lipomatoses have been reported in numerous organs and sites: pancreatic, adrenal, abdominal, epidural, mediastinal, epicardial… The aim of this review is to present the main types of lipomatosis and their physiopathological component, when it is known.

Asunto(s)

Lipoma , Lipomatosis , Humanos , Lipomatosis/patología , Lipoma/patología , Lipoma/genética , Lipomatosis Simétrica Múltiple/patología , Lipomatosis Simétrica Múltiple/diagnóstico , Lipodistrofia/patología , Lipodistrofia/genética , Tejido Adiposo/patología , Adiposis Dolorosa/patología , Adiposis Dolorosa/diagnóstico

RESUMEN

Lipodystrophic syndromes are acquired or genetic rare diseases, characterized by a generalized or partial lack of adipose tissue leading to metabolic alterations linked to strong insulin resistance. They are probably underdiagnosed, especially for partial forms. They are characterized by a lack of adipose tissue or a lack of adipose development leading to metabolic disorders associated with often severe insulin resistance, hypertriglyceridemia and hepatic steatosis. In partial forms of lipodystrophy, these mechanisms are aggravated by excess visceral adipose tissue and/or subcutaneous adipose tissue in the upper part of the body. Diagnosis is based on clinical examination, pathological context and comorbidities, and on results of metabolic investigations and genetic analyses, which together determine management and genetic counseling. Early lifestyle and dietary measures focusing on regular physical activity, and balanced diet avoiding excess energy intake are crucial. They are accompanied by multidisciplinary follow-up adapted to each clinical form. When standard treatments have failed to control metabolic disorders, the orphan drug metreleptin, an analog of leptin, can be effective in certain forms of lipodystrophy syndromes.

Asunto(s)

Lipodistrofia , Humanos , Lipodistrofia/terapia , Lipodistrofia/diagnóstico , Lipodistrofia/etiología , Lipodistrofia/genética , Resistencia a la Insulina , Lipodistrofia Parcial Familiar/terapia , Lipodistrofia Parcial Familiar/diagnóstico , Lipodistrofia Parcial Familiar/genética , Lipodistrofia Parcial Familiar/complicaciones , Tejido Adiposo/patología , Leptina/uso terapéutico , Leptina/análogos & derivados , Estilo de Vida

RESUMEN

Obesity has emerged as a prominent risk factor for the development of malignant tumors. However, the existing literature on the role of adipocytes in the tumor microenvironment (TME) to elucidate the correlation between obesity and cancer remains insufficient. Here, we aim to investigate the formation of cancer-associated adipocytes (CAAs) and their contribution to tumor growth using mouse models harboring dysfunctional adipocytes. Specifically, we employ adipocyte-specific BECN1 KO (BaKO) mice, which exhibit lipodystrophy due to dysfunctional adipocytes. Our results reveal the activation of YAP/TAZ signaling in both CAAs and BECN1-deficient adipocytes, inducing adipocyte dedifferentiation and formation of a malignant TME. The additional deletion of YAP/TAZ from BaKO mice significantly restores the lipodystrophy and inflammatory phenotypes, leading to tumor regression. Furthermore, mice fed a high-fat diet (HFD) exhibit decreased BECN1 and increased YAP/TAZ expression in their adipose tissues. Treatment with the YAP/TAZ inhibitor, verteporfin, suppresses tumor progression in BaKO and HFD-fed mice, highlighting its efficacy against mice with metabolic dysregulation. Overall, our findings provide insights into the key mediators of CAA and their significance in developing a TME, thereby suggesting a viable approach targeting adipocyte homeostasis to suppress cancer growth.

Asunto(s)

Proteínas Adaptadoras Transductoras de Señales , Adipocitos , Dieta Alta en Grasa , Ratones Noqueados , Proteínas Coactivadoras Transcripcionales con Motivo de Unión a PDZ , Microambiente Tumoral , Proteínas Señalizadoras YAP , Animales , Ratones , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Adipocitos/metabolismo , Adipocitos/patología , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Transformación Celular Neoplásica/metabolismo , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/patología , Dieta Alta en Grasa/efectos adversos , Progresión de la Enfermedad , Lipodistrofia/metabolismo , Lipodistrofia/patología , Lipodistrofia/genética , Ratones Endogámicos C57BL , Neoplasias/metabolismo , Neoplasias/patología , Neoplasias/genética , Obesidad/metabolismo , Obesidad/patología , Transducción de Señal , Transactivadores/metabolismo , Transactivadores/genética , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Verteporfina/farmacología , Proteínas Señalizadoras YAP/metabolismo

RESUMEN

Generalized lipodystrophy is a feature of various hereditary disorders, often leading to a progeroid appearance. In the present study we identified a missense and a frameshift variant in a compound heterozygous state in SUPT7L in a boy with intrauterine growth retardation, generalized lipodystrophy, and additional progeroid features. SUPT7L encodes a component of the transcriptional coactivator complex STAGA. By transcriptome sequencing, we showed the predicted missense variant to cause aberrant splicing, leading to exon truncation and thereby to a complete absence of SUPT7L in dermal fibroblasts. In addition, we found altered expression of genes encoding DNA repair pathway components. This pathway was further investigated and an increased rate of DNA damage was detected in proband-derived fibroblasts and genome-edited HeLa cells. Finally, we performed transient overexpression of wildtype SUPT7L in both cellular systems, which normalizes the number of DNA damage events. Our findings suggest SUPT7L as a novel disease gene and underline the link between genome instability and progeroid phenotypes.

Asunto(s)

Retardo del Crecimiento Fetal , Lipodistrofia Generalizada Congénita , Factores de Transcripción , Humanos , Masculino , Daño del ADN , Reparación del ADN/genética , Retardo del Crecimiento Fetal/genética , Fibroblastos/metabolismo , Células HeLa , Lipodistrofia/genética , Lipodistrofia Generalizada Congénita/genética , Mutación con Pérdida de Función , Mutación Missense , Factores de Transcripción/genética

RESUMEN

Adipose dysfunction in lipodystrophic SEIPIN deficiency is associated with multiple metabolic disorders and increased risks of developing cardiovascular diseases, such as atherosclerosis, cardiac hypertrophy, and heart failure. Recently, adipose transplantation has been found to correct adipose dysfunction and metabolic disorders in lipodystrophic Seipin knockout mice; however, whether adipose transplantation could improve lipodystrophy-associated cardiovascular consequences is still unclear. Here, we aimed to explore the effects of adipose transplantation on lipodystrophy-associated metabolic cardiovascular diseases in Seipin knockout mice crossed into atherosclerosis-prone apolipoprotein E (Apoe) knockout background. At 2 months of age, lipodystrophic Seipin/Apoe double knockout mice and nonlipodystrophic Apoe knockout controls were subjected to adipose transplantation or sham operation. Seven months later, mice were euthanized. Our data showed that although adipose transplantation had no significant impact on endogenous adipose atrophy or gene expression, it remarkably increased plasma leptin but not adiponectin concentration in Seipin/Apoe double knockout mice. This led to significantly reduced hyperlipidemia, hepatic steatosis, and insulin resistance in Seipin/Apoe double knockout mice. Consequently, atherosclerosis burden, intraplaque macrophage infiltration, and aortic inflammatory gene expression were all attenuated in Seipin/Apoe double knockout mice with adipose transplantation. However, adipocyte morphology, macrophage infiltration, or fibrosis of the perivascular adipose tissue was not altered in Seipin/Apoe double knockout mice with adipose transplantation, followed by no significant improvement of vasoconstriction or relaxation. In conclusion, we demonstrate that adipose transplantation could alleviate lipodystrophy-associated metabolic disorders and atherosclerosis but has an almost null impact on perivascular adipose abnormality or vascular dysfunction in lipodystrophic Seipin/Apoe double knockout mice.NEW & NOTEWORTHY Adipose transplantation (AT) reverses multiply metabolic derangements in lipodystrophy, but whether it could improve lipodystrophy-related cardiovascular consequences is unknown. Here, using Seipin/Apoe double knockout mice as a lipodystrophy disease model, we showed that AT partially restored adipose functionality, which translated into significantly reduced atherosclerosis. However, AT was incapable of reversing perivascular adipose abnormality or vascular dysfunction. The current study provides preliminary experimental evidence on the therapeutic potential of AT on lipodystrophy-related metabolic cardiovascular diseases.

Asunto(s)

Tejido Adiposo , Aterosclerosis , Subunidades gamma de la Proteína de Unión al GTP , Lipodistrofia , Ratones Noqueados , Animales , Ratones , Tejido Adiposo/metabolismo , Tejido Adiposo/trasplante , Apolipoproteínas E/genética , Apolipoproteínas E/deficiencia , Apolipoproteínas E/metabolismo , Aterosclerosis/genética , Aterosclerosis/metabolismo , Aterosclerosis/patología , Subunidades gamma de la Proteína de Unión al GTP/deficiencia , Subunidades gamma de la Proteína de Unión al GTP/genética , Subunidades gamma de la Proteína de Unión al GTP/metabolismo , Proteínas de Unión al GTP Heterotriméricas/genética , Proteínas de Unión al GTP Heterotriméricas/metabolismo , Resistencia a la Insulina , Leptina/sangre , Leptina/metabolismo , Lipodistrofia/metabolismo , Lipodistrofia/genética , Lipodistrofia/patología , Ratones Endogámicos C57BL

RESUMEN

Seipin (BSCL2), a conserved endoplasmic reticulum protein, plays a critical role in lipid droplet (LD) biogenesis and in regulating LD morphology, pathogenic variants of which are associated with Berardinelli-Seip congenital generalized lipodystrophy type 2 (BSCL2). To model BSCL2 disease, we generated an orthologous BSCL2 variant, seip-1(A185P), in Caenorhabditis elegans. In this study, we conducted an unbiased chemical mutagenesis screen to identify genetic suppressors that restore embryonic viability in the seip-1(A185P) mutant background. A total of five suppressor lines were isolated and recovered from the screen. The defective phenotypes of seip-1(A185P), including embryonic lethality and impaired eggshell formation, were significantly suppressed in each suppressor line. Two of the five suppressor lines also alleviated the enlarged LDs in the oocytes. We then mapped a suppressor candidate gene, lmbr-1, which is an ortholog of human limb development membrane protein 1 (LMBR1). The CRISPR/Cas9 edited lmbr-1 suppressor alleles, lmbr-1(S647F) and lmbr-1(P314L), both significantly suppressed embryonic lethality and defective eggshell formation in the seip-1(A185P) background. The newly identified suppressor lines offer valuable insights into potential genetic interactors and pathways that may regulate seipin in the lipodystrophy model.

Asunto(s)

Subunidades gamma de la Proteína de Unión al GTP , Proteínas de Unión al GTP Heterotriméricas , Lipodistrofia Generalizada Congénita , Lipodistrofia , Animales , Humanos , Lipodistrofia Generalizada Congénita/genética , Lipodistrofia Generalizada Congénita/metabolismo , Proteínas de Unión al GTP Heterotriméricas/genética , Proteínas de Unión al GTP Heterotriméricas/metabolismo , Subunidades gamma de la Proteína de Unión al GTP/genética , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Lipodistrofia/genética

RESUMEN

Background: Mandibuloacral dysplasia (MAD) syndrome is a rare genetic disease. Several progeroid syndromes including mandibuloacral dysplasia type A (MADA), mandibuloacral dysplasia type B(MADB), Hutchinson-Gilford progeria (HGPS) and mandibular hypoplasia, deafness, and lipodystrophy syndrome (MDPL) have been reported previously. A novel MAD progeroid syndrome (MADaM) has recently been reported. So far, 7 cases of MADaM diagnosed with molecular diagnostics have been reported in worldwide. In the Chinese population, cases of MAD associated with the MTX2 variant have never been reported. Methods: The clinical symptoms and the genetic analysis were identified and investigated in patients presented with the disease. In addition, we analyzed and compared 7 MADaM cases reported worldwide and summarized the progeroid syndromes reported in the Chinese population to date. Results: The present study reports a case of a novel homozygous mutation c.378 + 1G > A in the MTX2 gene, which has not been previously reported in the literature. Patients present with early onset and severe symptoms and soon after birth are found to have growth retardation. In addition to the progeroid features, skeletal deformities, generalized lipodystrophy reported previously, and other multisystem involvement, e.g. hepatosplenic, renal, and cardiovascular system, this case was also reported to have combined hypogammaglobulinemia. She has since been admitted to the hospital several times for infections. Among 22 previously reported progeroid syndromes, 16/22 were MADA or HGPS caused by LMNA gene mutations, and the homozygous c.1579C > T (p.R527C) mutation may be a hot spot mutation for MAD in the Chinese population. MAD and HGPS mostly present in infancy with skin abnormalities or alopecia, MDPL mostly presents in school age with growth retardation as the first manifestation, and is often combined with an endocrine metabolism disorder after several decades. Conclusion: This is the first case of MAD syndrome caused by mutations in MTX2 gene reported in the Chinese population. MTX2 gene c.378 + 1G > A homozygous mutation has not been previously reported and the report of this patient expands the spectrum of MTX2 mutations. In addition, we summarized the genotypes and clinical characteristics of patients with progeroid syndromes in China.

Asunto(s)

Lipodistrofia , Progeria , Femenino , Humanos , Progeria/genética , Progeria/complicaciones , Progeria/diagnóstico , Lipodistrofia/genética , Síndrome , Mutación , Enfermedades Raras , Trastornos del Crecimiento/complicaciones

RESUMEN

BACKGROUND: Congenital generalized lipodystrophy (CGL) is a rare inherited disease characterized by a near-total absence of adipose tissue and is associated with organ system abnormalities and severe metabolic complications. Here, we have analyzed the disease characteristics of the largest CGL cohort from the Middle East and North Africa (MENA) who have not received lipodystrophy-specific treatment. METHODS: CGL was diagnosed clinically by treating physicians through physical assessment and supported by genetic analysis, fat loss patterns, family history, and the presence of parental consanguinity. Data were obtained at the time of patient diagnosis and during leptin-replacement naïve follow-up visits as permitted by available medical records. RESULTS: Data from 43 patients with CGL (37 females, 86%) were collected from centers located in eight countries. The mean (median, range) age at diagnosis was 5.1 (1.0, at birth-37) years. Genetic analysis of the overall cohort showed that CGL1 (n = 14, 33%) and CGL2 (n = 18, 42%) were the predominant CGL subtypes followed by CGL4 (n = 10, 23%); a genetic diagnosis was unavailable for one patient (2%). There was a high prevalence of parental consanguinity (93%) and family history (67%) of lipodystrophy, with 64% (n = 25/39) and 51% (n = 20/39) of patients presenting with acromegaloid features and acanthosis nigricans, respectively. Eighty-one percent (n = 35/43) of patients had at least one organ abnormality; the most frequently affected organs were the liver (70%, n = 30/43), the cardiovascular system (37%, n = 16/43) and the spleen (33%, n = 14/43). Thirteen out of 28 (46%) patients had HbA1c > 5.7% and 20/33 (61%) had triglyceride levels > 2.26 mmol/L (200 mg/dl). Generally, patients diagnosed in adolescence or later had a greater severity of metabolic disease versus those diagnosed during childhood; however, metabolic and organ system abnormalities were observed in a subset of patients diagnosed before or at 1 year of age. CONCLUSIONS: This analysis suggests that in addition to the early onset of fat loss, family history and high consanguinity enable the identification of young patients with CGL in the MENA region. In patients with CGL who have not received lipodystrophy-specific treatment, severe metabolic disease and organ abnormalities can develop by late childhood and worsen with age.

Asunto(s)

Lipodistrofia Generalizada Congénita , Lipodistrofia , Femenino , Adolescente , Recién Nacido , Humanos , Niño , Lipodistrofia Generalizada Congénita/epidemiología , Lipodistrofia Generalizada Congénita/genética , Lipodistrofia Generalizada Congénita/complicaciones , Lipodistrofia/epidemiología , Lipodistrofia/genética , Tejido Adiposo , África del Norte/epidemiología , Medio Oriente/epidemiología

RESUMEN

Protease inhibitors (PIs) are associated with an incidence of lipodystrophy among people living with HIV(PLHIV). Lipodystrophiesare characterised by the loss of adipose tissue. Evidence suggests that a patient's lipodystrophy phenotype is influenced by genetic mutation, age, gender, and environmental and genetic factors, such as single-nucleotide variants (SNVs). Pathogenic variants are considered to cause a more significant loss of adipose tissue compared to non-pathogenic. Lipid metabolising enzymes and transporter genes have a role in regulating lipoprotein metabolism and have been associated with lipodystrophy in HIV-infected patients (LDHIV). The long-term effect of the lipodystrophy syndrome is related to cardiovascular diseases (CVDs). Hence, we determined the SNVs of lipid metabolising enzymes and transporter genes in a total of 48 patient samples, of which 24 were with and 24 were without HIV-associated lipodystrophy (HIVLD) using next-generation sequencing. A panel of lipid metabolism, transport and elimination genes were sequenced. Three novel heterozygous non-synonymous variants at exon 8 (c.C1400A:p.S467Y, c.G1385A:p.G462E, and c.T1339C:p.S447P) in the ABCB6 gene were identified in patients with lipodystrophy. One homozygous non-synonymous SNV (exon5:c.T358C:p.S120P) in the GRN gene was identified in patients with lipodystrophy. One novelstop-gain SNV (exon5:c.C373T:p.Q125X) was found in the GRN gene among patients without lipodystrophy. Patients without lipodystrophy had one homozygous non-synonymous SNV (exon9:c.G1462T:p.G488C) in the ABCB6 gene. Our findings suggest that novel heterozygous non-synonymous variants in the ABCB6 gene may contribute to defective protein production, potentially intensifying the severity of lipodystrophy. Additionally, identifying a stop-gain SNV in the GRN gene among patients without lipodystrophy implies a potential role in the development of HIVLD.

Asunto(s)

Infecciones por VIH , Síndrome de Lipodistrofia Asociada a VIH , Lipodistrofia , Humanos , Síndrome de Lipodistrofia Asociada a VIH/genética , Síndrome de Lipodistrofia Asociada a VIH/complicaciones , Lipodistrofia/genética , Lipodistrofia/complicaciones , Lipodistrofia/epidemiología , Mutación , Tejido Adiposo , Lípidos , Infecciones por VIH/complicaciones , Infecciones por VIH/genética , Transportadoras de Casetes de Unión a ATP/genética , Progranulinas/genética

RESUMEN

Adipocytes are the primary sites for fatty acid storage, but the synthesis rate of fatty acids is very low. The physiological significance of this phenomenon remains unclear. Here, we show that surplus fatty acid synthesis in adipocytes induces necroptosis and lipodystrophy. Transcriptional activation of FASN elevates fatty acid synthesis, but decreases NADPH level and increases ROS production, which ultimately leads to adipocyte necroptosis. We identify MED20, a subunit of the Mediator complex, as a negative regulator of FASN transcription. Adipocyte-specific male Med20 knockout mice progressively develop lipodystrophy, which is reversed by scavenging ROS. Further, in a murine model of HIV-associated lipodystrophy and a human patient with acquired lipodystrophy, ROS neutralization significantly improves metabolic disorders, indicating a causal role of ROS in disease onset. Our study well explains the low fatty acid synthesis rate in adipocytes, and sheds light on the management of acquired lipodystrophy.

Asunto(s)

Adipocitos , Lipodistrofia , Masculino , Ratones , Humanos , Animales , Especies Reactivas de Oxígeno/metabolismo , Adipocitos/metabolismo , Lipodistrofia/genética , Lipodistrofia/metabolismo , Ácidos Grasos/metabolismo , Estrés Oxidativo , Ratones Noqueados

RESUMEN

BACKGROUND: Lipodystrophy is a relatively rare, complex disease characterised by a deficiency of adipose tissue and can present as either generalised lipodystrophy (GLD) or partial lipodystrophy (PLD). The prevalence of this disease varies by region. This study aimed to identify the genetic variations associated with lipodystrophy in the southern part of Saudi Arabia. METHODOLOGY:  We conducted a retrospective study by recruiting nine patients from six families, recruiting the proband whole exome sequencing results or any other genetic test results, screening other family members using Sanger sequencing and analysing the carrier status of the latter. These patients were recruited from the Endocrinology and Diabetes Clinic at Jazan General Hospital and East Jeddah Hospital, both in the Kingdom of Saudi Arabia. RESULT: Eight patients were diagnosed with GLD, and one was diagnosed with PLD. Of the six families, four were consanguineously married from the same tribe, while the remaining belonged to the same clan. The majority of GLD patients had an AGPAT2 c.158del mutation, but some had a BSCL2 c.942dup mutation. The single PLD case had a PPARG c.1024C > T mutation but no family history of the disease. In all families evaluated in this study, some family members were confirmed to be carriers of the mutation observed in the corresponding patient. CONCLUSION:  Familial screening of relatives of patients with rare, autosomal recessive diseases, such as lipodystrophy, especially when there is a family history, allows the implementation of measures to prevent the onset or reduced severity of disease and reduces the chances of the pathogenic allele being passed onto future generations. Creating a national registry of patients with genetic diseases and carriers of familial pathogenic alleles will allow the assessment of preventive measures and accelerate disease intervention via gene therapy.

Asunto(s)

Pruebas Genéticas , Enfermedades Raras , Humanos , Arabia Saudita/epidemiología , Masculino , Femenino , Estudios Retrospectivos , Enfermedades Raras/diagnóstico , Enfermedades Raras/genética , Enfermedades Raras/epidemiología , Pruebas Genéticas/métodos , Pruebas Genéticas/estadística & datos numéricos , Adulto , Adolescente , Lipodistrofia/genética , Lipodistrofia/epidemiología , Lipodistrofia/diagnóstico , Lipodistrofia/prevención & control , Niño , Linaje , Adulto Joven , Mutación , Secuenciación del Exoma/métodos , Persona de Mediana Edad

RESUMEN

BACKGROUND: Type 2 diabetes (T2DM) is genetically heterogenous, driven by beta cell dysfunction and insulin resistance. Insulin resistance drives the development of cardiometabolic complications and is typically associated with obesity. A group of common variants at eleven loci are associated with insulin resistance and risk of both type 2 diabetes and coronary artery disease. These variants describe a polygenic correlate of lipodystrophy, with a high metabolic disease risk despite a low BMI. OBJECTIVES: In this cross-sectional study, we sought to investigate the association of a polygenic risk score composed of eleven lipodystrophy variants with anthropometric, glycaemic and metabolic traits in an island population characterised by a high prevalence of both obesity and type 2 diabetes. METHODS: 814 unrelated adults (n = 477 controls and n = 337 T2DM cases) of Maltese-Caucasian ethnicity were genotyped and associations with phenotypes explored. RESULTS: A higher polygenic lipodystrophy risk score was correlated with lower adiposity indices (lower waist circumference and body mass index measurements) and higher HOMA-IR, atherogenic dyslipidaemia and visceral fat dysfunction as assessed by the visceral adiposity index in the DM group. In crude and covariate-adjusted models, individuals in the top quartile of polygenic risk had a higher T2DM risk relative to individuals in the first quartile of the risk score distribution. CONCLUSION: This study consolidates the association between polygenic lipodystrophy risk alleles, metabolic syndrome parameters and T2DM risk particularly in normal-weight individuals. Our findings demonstrate that polygenic lipodystrophy risk alleles drive insulin resistance and diabetes risk independent of an increased BMI.

Asunto(s)

Diabetes Mellitus Tipo 2 , Puntuación de Riesgo Genético , Lipodistrofia , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Índice de Masa Corporal , Estudios Transversales , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/epidemiología , Resistencia a la Insulina/genética , Lipodistrofia/genética , Lipodistrofia/epidemiología , Malta/epidemiología , Obesidad/genética , Obesidad/complicaciones , Obesidad/epidemiología , Prevalencia

RESUMEN

CONTEXT: Lipodystrophy syndromes are a heterogeneous group of rare genetic or acquired disorders characterized by generalized or partial loss of adipose tissue. LMNA-related lipodystrophy syndromes are classified based on the severity and distribution of adipose tissue loss. OBJECTIVE: We aimed to annotate all clinical and metabolic features of patients with lipodystrophy syndromes carrying pathogenic LMNA variants and assess potential genotype-phenotype relationships. METHODS: We retrospectively reviewed and analyzed all our cases (n = 115) and all published cases (n = 379) curated from 94 studies in the literature. RESULTS: The study included 494 patients. The most common variants in our study, R482Q and R482W, were associated with similar metabolic characteristics and complications though those with the R482W variant were younger (aged 33 [24] years vs 44 [25] years; P < .001), had an earlier diabetes diagnosis (aged 27 [18] vs 40 [17] years; P < .001) and had lower body mass index levels (24 [5] vs 25 [4]; P = .037). Dyslipidemia was the earliest biochemical evidence described in 83% of all patients at a median age of 26 (10) years, while diabetes was reported in 61% of cases. Among 39 patients with an episode of acute pancreatitis, the median age at acute pancreatitis diagnosis was 20 (17) years. Patients who were reported to have diabetes had 3.2 times, while those with hypertriglyceridemia had 12.0 times, the odds of having pancreatitis compared to those who did not. CONCLUSION: This study reports the largest number of patients with LMNA-related lipodystrophy syndromes to date. Our report helps to quantify the prevalence of the known and rare complications associated with different phenotypes and serves as a comprehensive catalog of all known cases.

Asunto(s)

Diabetes Mellitus , Lipodistrofia , Pancreatitis , Humanos , Adulto , Adulto Joven , Mutación , Estudios Retrospectivos , Enfermedad Aguda , Lamina Tipo A/genética , Lipodistrofia/diagnóstico , Lipodistrofia/epidemiología , Lipodistrofia/genética , Diabetes Mellitus/genética